The lowest price at which a seller is willing to part with a security. On the level 2 montage, the Ask represents the supply available for immediate purchase. Aggressive buyers "hit the ask" to ensure immediate fill, effectively crossing the spread.

The highest price a buyer is willing to pay for a security. The Bid represents the "floor" of immediate liquidity. Defensive sellers "hit the bid" to exit positions quickly, especially during periods of high-velocity downward price action.

The numerical difference between the highest bid and the lowest ask. In highly liquid markets (e.g., Apple stock or EUR/USD), the spread is typically one cent or one pip. In low-liquidity environments, a wide spread acts as a "participation tax," requiring the price to move significantly in the trader's favor just to reach break-even.

The degree to which an asset can be quickly bought or sold in the market without affecting its price. For day traders, liquidity is the primary safety mechanism; high liquidity ensures that stop-losses are filled with minimal slippage.

An order to buy or sell a security at a specific price or better. While it guarantees the price of execution, it does not guarantee a fill. Professional traders use limit orders to avoid overpaying for entry or receiving an unfavorable exit during volatility.

An order to buy or sell immediately at the best available current price. Market orders prioritize speed over price precision. In volatile markets, using a market order can result in "slippage," where the actual fill price is significantly worse than the price displayed on the screen.

The difference between the expected price of a trade and the price at which the trade is actually executed. Slippage frequently occurs during high-impact news events or during the "opening drive" of the market session when volatility outpaces the order book's liquidity.

A technological infrastructure that allows traders to bypass the broker’s internal "dealing desk" and send orders directly to the exchange’s order book (e.g., NASDAQ or NYSE). DMA is essential for high-frequency strategies where execution latency is a critical variable.

The primary benchmark for institutional execution. VWAP calculates the average price an asset has traded at throughout the day, weighted by volume. Prices above VWAP suggest bullish sentiment, while prices below suggest bearish dominance. Many intraday strategies treat VWAP as "true north."

A volatility indicator that measures the average move of an asset over a specific period. Day traders use ATR to set "volatility-adjusted" stop-losses, ensuring that a stop is placed outside the "normal" noise of the market session.

A momentum oscillator that measures the speed and change of price movements. While retail traders often use it for "overbought/oversold" signals, professionals look for "divergence"—where price makes a new high but RSI does not, signaling momentum exhaustion.

A FINRA regulation in the United States requiring traders who execute four or more day trades in a five-business-day period to maintain a minimum of $25,000 in equity. Failure to meet this requirement results in an account freeze for 90 days.

The use of borrowed funds to increase a trader's position size beyond what they could afford with their cash balance. In the US, day traders are typically granted 4:1 intraday leverage. While leverage amplifies returns, it equally accelerates account depletion.

The minimum amount of equity a trader must maintain in their account to keep a leveraged position open. If the account falls below this level due to losses, a "Margin Call" is issued, requiring immediate deposit or resulting in forced liquidation.

A price movement that breaks above a resistance level, attracting buyers, only to reverse violently and trap those buyers in losing positions. This is often an institutional move to "generate liquidity" for a large sell order.

Private exchanges or forums for trading securities that are not accessible to the investing public. Dark pools allow institutional investors to trade large blocks of shares without revealing their intentions to the open market, though their transactions are eventually reported on the consolidated tape.

Algorithmic trading characterized by high speeds, high turnover rates, and high order-to-transaction ratios. HFT systems compete on microseconds and account for the vast majority of intraday liquidity in modern electronic markets.